Bump actions/checkout from 6 to 7

.github/workflows/buildtest.yml

@@ -35,7 +35,7 @@ jobs:
 
     steps:
       - name: Git clone
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Build Carl-parser from Dockerfile
         run: |
           docker build -t movesrwth/carl-parser:ci . \
@@ -82,14 +82,14 @@ jobs:
         with:
           xcode-version: ${{ matrix.config.xcode }}
       - name: Git clone
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Install dependencies
         # cmake, gmp and java are already installed
         run: |
           brew update
           brew install boost cln ginac
       - name: Git clone Carl-storm
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           repository: stormchecker/carl-storm
           path: carl-storm
@@ -131,7 +131,7 @@ jobs:
             }
     steps:
       - name: Git clone
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Build Carl-storm from Dockerfile
         run: |
           docker build -t movesrwth/carl-parser:${{ matrix.build_type.dockerTag }} . \